1. Field of the Invention
The present invention relates to a process for producing a liquid ejection head for ejecting a liquid, preferably to an ink jet recording head for ejecting a droplet of a recording liquid such as ink.
2. Description of the Related Art
There is, among other inkjet printing systems, a system called a “side shooter type print head” in which a liquid droplet of ink is ejected perpendicular to a substrate on which an ejection energy generating element is formed. The side shooter type print head has rapidly become popular these few years because it can print using a small liquid droplet by shortening the distance between an ejection energy generating element and an orifice.
Further, recently, with development of a recording technology for high resolution and high image quality, it is demanded that the distance between an ejection energy generating element and an orifice plane be more accurate.
Japanese Patent Application Laid-Open No. H11-138817 discloses that an ink jet recording head having an excellent flatness of an orifice plane is manufactured by providing a base 105 on a substrate 101 to surround a mold pattern 111 of an ink flow path when disposing a covering layer, as illustrated in FIGS. 5A and 5B.
However, a demand for further high speed printing causes an increase in the number of nozzles and length of an ink flow path, and the area of an ink flow path in a chip accordingly tends to be larger. When the area of the ink flow path is larger, the coatability of a covering layer constituting a nozzle becomes lower, and there may be a variation in distance between an ejection energy generating element and an orifice plane, so that the flatness of the orifice plane can be lowered.
If the method described in Japanese Patent Application Laid-Open No. H11-138817 is used as a solution for the problem described above, the flatness of the orifice plane, as illustrated in FIG. 6A, can be improved by widening the base 105 and shortening the distance between the mold pattern 111 of the ink flow path and the base 105. However this method, as shown in FIGS. 6B and 6C, provides an eaves structure on the side of the ink flow path, and an orifice plate 112 may be accordingly damaged.
Therefore, an object of the present invention is to provide a process for producing a print head having an excellent flatness of an orifice plane and a high strength of an orifice plate.